The present invention relates to a compressor used for, e.g., an on-vehicle air conditioner or a water heater.
The on-vehicle air conditioner or the water heater has conventionally comprised a refrigerant circuit constituted of a heat exchanger and a compressor. For example, the compressor comprises an electric element, and first and second compression elements connected to the electric element, and an airtight container which receives the electric element and the compression elements. The compressor drives the compression elements by the electric element, thereby compressing an introduced low-pressure refrigerant at the first compression element and feeing the refrigerant into the airtight container by intermediate pressure. Further, the compressor compresses the refrigerant of the intermediate pressure in the airtight container at the second compression element, and discharges the refrigerant by high pressure. A plurality of pipes are connected to the airtight container. That is, the refrigerant is introduced through the pipe to the first compression element, and discharged through the pipe (e.g., see Japanese Patent Application Laid-Open No. 2003-120561). Each of the pipes comprises, e.g., a cylindrical pipe main body, and a jaw-like flange portion formed in a tip of the pipe main body. The pipe is mounted to the airtight container by fixing the flange portion of the pipe to a surface of the airtight container through a bolt. As described above, however, the airtight container is filled with the refrigerant of the intermediate pressure. Consequently, when a tip of the bolt which connects the pipe to the airtight container projects therein, i.e., when the bolt penetrates the airtight container, there occurs a problem of leakage of the refrigerant of the intermediate pressure from an engaging portion of the bolt with the airtight container to the outside.
To solve the problem, the projection of the bolt in the airtight container is prevented by forming a portion of the airtight container connected to the pipe (referred to as pipe connection portion, hereinafter) thicker than other portions by cutting or welding.
However, even when the pipe connection portion is formed by cutting, a shape of the airtight container becomes complex, and manufacturing costs of the compressor increase. Furthermore, even when the pipe connection portion is formed by welding another member to the airtight container, welding heat causes a drop in strength of the airtight container.